Heat oven to 350. Spray a lg baking sheet w/ cooking spray. In lg skillet, over medium heat, cook garlic, and green onions in oil until tender, stirring occasionally. Stir in chicken, salt and pepper. Stir in salsa.
Arrange tortilla chips on baking sheet. Spoon chicken mix over chips. Top w/ cheese and tomato. Bake 10 mins, or until cheese is melted. Serve topped w/ sour cream dollops.